Variable throw rocker

ABSTRACT

Actuating means for an adjustable taper mandrel assembly in which the operating means comprises a longitudinally reciprocable rod. The actuating means includes having a first end coupled to the rod and being adapted in response to actuation of said arm to execute a linear reciprocating motion from a datum position at an extremity of said motion. The arm is mounted intermediate its ends on floating fulcrum means which includes adjustment means for varying the position of the fulcrum with respect to the datum position of said first arm end and in a plane containing or parallel to the said datum position. The arrangement is such that the throw of the longitudinal rod can be varied by operation of said adjustment means while maintaining said one extremity of said motion of said first end in said datum position, thereby varying the taper imparted to the mandrel assembly in its expanded position.

O United States Patent 1191 1111 3,847,007

Brownbill Nov. 12, 1974 VARIABLE THROW ROCKER Primary Examiner-C. W. Lanham Assistant Examiner-Gene P. Crosby [76] lnvemor' Attorney. Agent, or Firm-Cushman, Darby &

England Cushman [22] Filed: June 14, 1973 [57] ABSTRACT [21] Appl. No.: 369,880

Actuatmg means for an ad ustable taper mandrel as- Related Application Data sembly in which the operating means comprises a lon- [63] Continuation-impart of Ser. No. 168,581, Aug. 3, gitudinally reciprocable rod. The actuating means inl97l. a u cludes having a first end coupled to the rod and being adapted in response to actuation of said arm to exe- [30] Foreign Application Priority Data cute a linear reciprocating motion from a datum posi- Aug. 11, 1970 Great Britain 38663/70 tien at an extremity of said motion The arm is mounted intermediate its ends on floating fulcrum [52] US. Cl 72/393, 72/399, 72/446, means which in l jus ment m n f ying 72/450, 72/452 the position of the fulcrum with respect to the datum [51] Int. Cl B210 41/02 p sit n f said fi s m nd and in a plane ta n ng [58] Field of Search 72/393, 399, 450, 452, r parallel to th i datum position. Th ng 72/446, 454 ment is such that the throw of the longitudinal rod can be varied by operation of said adjustment means while [56] R fer Cit d maintaining said one extremity of said motion of said UNITED STATES PATENTS first end in said datum position, thereby varying the 2,444,601 7/1948 Hansen 72 393 fi to the mandle' assembly m 3,102,502 9/1963 Seeloff 72 393 pan 6 3,690,14l 9/1972 Brownbill 72/452 8 Claims, 3 Drawing Figures VARIABLE THROW ROCKER This application is a continuation-in-part of my copending application Ser. No. 168,581, filed Aug. 3, 1971, now abandoned.

The present invention relates to actuating means for a mandrel assembly, and may be particularly utilized with a mandrel assembly of the type comprising aplurality of discrete longitudinal segments which together constitute a segment assembly to define a generally cylindrical mandrel surface, hinge means provided at or towards one end of said segment assembly to permit each of said segments to hinge radially outwardly of the longitudinal axis of said cylindrical surface at least towards one end thereof, expansion means adapted to urge said segments outwardly and about said hinge means at said one end of the segment so that the outer surfaces of the segment together define a taper, and operating means in the form of a reciprocable rod for producing relative motion between said segments and said expansion means between an inoperative position in which the segments define a substantially cylindrical mandrel surface and an expanded position in which the segments define a taper surface.

It will be appreciated that when such a mandrel is employed to provide tapered collapsible tubes it is necessary to provide a different taper for different sizes of tube. The size of the taper is directly proportional to the throw of the operating rod which controls the extent to which the expandable end of the segment assembly is drawn onto the frusto-conical expanding member. It will be further appreciated that in an automated line for the manufacture and packing of such flared tube it is necessary that in each instant the extremity of the mandrel and hence the driven portion of the operating rod be returned to the same datum position irrespective of the throw applied to the operating rod for adjustment of varying tapers to the particular tubes concerned.

According to the present invention, there is provided an actuating means for a mandrel assembly of the type described in which the operating means includes a longitudinal rod adapted to draw said segment assembly onto said expansion means. The actuating means comprises a variable mechanism including a rocker arm adapted to drive said rod and having a first part and a second part, said first part being coupled to said rod and being adapted to execute a linear reciprocating motion from a datum position at an extremity of said motion in response to actuation of said arm, floating fulcrum means for said arm disposed intermediate said first and second parts and adjustment means for varying the position of said fulcrum with respect to the datum position of said first part and in a plane containing, or parallel to, the datum position of said first and said second parts, the arrangement being such that the throw of said longitudinal rod can be varied by operation of said adjustment means while maintaining said tween said second part of said arm and said cam track.

The arm may include intermediate said first and second parts, a longitudinal slideway accommodating a fulcrum pin assembly for relative sliding movement therein to provide the floating fulcrum means. The fulcrum pin assembly may be carried in a carriage which is adjustably supported on a bracket or support provided therefor said bracket or support having adjustment means for said carriage to move said fulcrum relative to the datum position of said first part.

The expansion means of the mandrel assembly generally comprises a frusto-conical element, and the operating means is arranged to provide relative motion between the segment assembly and the frusto-conical element so that on drawing one towards the other the segments are caused or allowed to hinge about said hinge means to define a taper mandrel surface. The operating means typically comprises a rod assembly provided with a fixed or a lost motion coupling to the segment assembly and executing a reciprocating motion in its longitudinal axis.

Following is a description by way of example and with reference to the accompanying formal drawings of apparatus in accordance with the present invention.

IN THE DRAWINGS FIG. 1 is a side view of a mandrel assembly and actuating means therefor in accordance with the present invention;

FIG. 2 is a transverse view partially in section of the rocker arm on the line 2-2 of FIG. 1; and

FIG. 3 is a transverse sectional view of a segmented mandrel assembly along line 33.

It will be appreciated that when such a mandrel is employed to provide tapered collapsible tubes it is necessary to provide a different taper for different sizes of tube. The size of the taper is directly proportional to the throw of the operating rod which controls the extent to which the expandable end of the segment assembly is drawn onto the frustoconical expanding member. It will be further appreciated that in an automated line for the manufacture and packing of such flared tubes it is necessary that in each instant the extremity of the mandrel and hence the driven portion of the operating rod be returned to the same datum position irrespective of the throw applied to the operating rod for adjustment of varying tapers to the particular tubes concerned.

The mandrel assembly is attached to a housing cylinder 10 having a generally cylindrical bore 11. The housing 10 is closed at its rearward end 12 by means of a threaded plug and is provided at its forward end with a bore 13 of reduced section which accommodates an operating rod 14 coupled to the mandrel assembly as fully described hereinafter. Cylinder 11 is provided with a pair of longitudinally disposed diametrically spaced slots 15 and bore 11 accommodate a piston member 16.

Piston member 16 is provided with a blind bore 17 at its forward end which is threaded on its inner surface and threadably engages the rearward end of operating rod 14, the arrangement being such that reciprocating movement of the piston member 16 is transmitted to the connecting rod 17. Towards its rearward end, the piston member 16 is provided with a transverse bore 18 aligned with slots 15. The bore 18in piston member 16 accommodates a connecting pin 20 rotatably connected with a rocker member 25.

The rocker member 25 comprises an elongate arm which depends generally downwardly of slots 15 and cylinder 10, the rocker arm 25 being bifurcated at its upper end 26 to terminate in an upwardly disposed yoke 27 having a pair of spaced arms 28. The spaced arms 28 are adapted to embrace cylinder each of the arms 28 having a bore 29 to accommodate connecting pin 20, the arrangement being such that the pin passes through one of arms 28 on yoke 27, enters the adjacent slot and cylinder 10, passes through bore 18 in piston member 16 and through the second slot 15 in cylinder 10 and through the second slot 15 in cylinder 10 and through the bore 29 in the second arm 28 of yoke 27, so that the rocker arm is pivotally connected to piston member 16.

The arm 25 has an intermediate portion 32 of generally rectangular cross-section which increases in crosssection towards its mid point. The lower portion 30 of arm 25 is of generally frusto-conical form and terminates at its lower end in a spheroidal ball portion 31 in tegral with the remainder of the arm.

Intermediate portion 32 of arm 25 is provided with a longitudinal slot 33 constituting a slideway as hereinafter described, the slot extending in the same longitudinal plane containing the bores 29 in each of the arms 28 of yoke 27.

A cam roller 35 is adapted to be rotated by motor means not shown. The cam roller 35 carries in its cylindrical surface 36 a continuous cam groove 37 which provides a throw of dimensions A between the forward extremity of the groove in roller 35 indicated at 37' and at the rearward extremity of the groove indicated by 37. The depth of each of the grooves is approximately 3 times the radius of the lower ball portion 31 of arm 25 to allow for entry of the ball further into the groove during operation. The datum position of the rocker arm 25 of which the cycle commences is deter mined by the rearward extremity of groove 37 in the cam roller 35 and the forward location of the connecting pin in slots 15 of cylinder 10.

A bracket is fixedly secured with respect to cylinder 10. The bracket carries towards each end upper and lower support elements 46 and 47 each of which carries a bore 48 disposed outwardly of an inclined rearward face 49 of the bracket. The support elements 46 and 47 are disposed at an angle to the horizontal and arranged so that the axis of each of bores 48 in each of the upper and lower support elements 46 and 47 respectively is substantially parallel with the longitudinal axis of arm 25 when in the datum position. The support elements 46 and 47 support a rotatable threaded shaft 55 carried in said bores 48 for rotation with respect to support elements 46 and 47. The bracket 45 has a smooth surface to its rearward face and which constitutes a slideway for a fulcrum carriage 50.

The fulcrum carriage 50 has an inclined forward face 51, adapted to co-operate with rearward surface 49 of bracket 45; the body of carriage 51 extending rearwardly and horizontally of bracket 45. The carriage 50 has an inclined threaded bore 54 substantially parallel to the forward face 51 of the carriage, which accommodates threaded shaft 55 passing through bore 54 and engaging with each of bores 48 in bracket supports 46 and 47 respectively. Rotation of shaft 55 with respect to brackets 46 and 47 causes movement of carriage element 50 along shaft 55 relative to bracket 45 and cylinder 10 thereby causing the fulcrum carriage to move in a direction parallel with a longitudinal axis of arm 25 when considered in its datum position.

5 The rearward part of carriage 50 is bifurcated towards its rearward end and terminates in a pair of spaced arms 63. The arms 63 are disposed on either side of rocker arm 25 and a bore in the end of each arm 63 is adapted to co-operate with longitudinal slot 33 in rocker arm 25. The bore in each of arms 63 carried on fulcrum carriage 50 accommodates a fulcrum pin 65 which is mounted in bushingssecured in the bores of each of arms 63. The fulcrum pin 65 carries, freely rotatable thereon, a slider element 66 of rectangular cross-section which extends through and engages with the longitudinal edges defining slot 33 in rocker arm 65, the arrangement being such that the position of the axis of fulcrum pin 65 is capable of relative longitudinal movement in slot 33 with respect to rocker arm 25.

The mandrel assembly comprises a generally cylindrical tube 68 defined by eight longitudinal segments 70 each subtending an angle of substantially 45 at the axis of the tube 68. Each segment 70 is defined by an outer areuate surface 72 and an inner areuate surface 74 and a pair of radial surfaces 76, the arrangement being such that the eight segments 70 together define a substantially cylindrical outer surface and a substantially cylindrical inner bore 78. Each segment 70 is provided in its inner surface towards its forward end but spaced rearwardly thereof, with a recess so that the eight segments which together constitute a segment assembly define a central bore in which the recesses constitute an expanded portion. The inner surface of each segment 70 is flared at its rearward end at 82 so that the segment assembly defines towards the rearward end an expanding frusto-conical passage 84.

The outer surface of each segment 70 is provided with a peripheral recess or rabbet 86 at the forward end extending into the forward face of each segment so that the segment assembly defines an annular peripheral recess at the forward end of the assembly. The outer surface of each segment is provided in its outer surface at its rearward end with a pair of spaced peripheral grooves 88, 90 which in the segment assembly defines a pair of peripheral grooves each adapted to receive a spring clip 116 which serves to bias the rearward end of the segment assembly to the cylindrical position.

Each segment 70 is machined towards its rearward end in its outer surface so that the arcuate portion of the outer surface defines an arc of radius greater than the radius of the outer areuate surface of the forward end, the arrangement being such that in the expanded position, the outer surface of the rear end of the segment assembly is substantially circular in section.

The central bore 78 of the segment assembly is adapted to accommodate a longitudinal support rod 92 extending therethrough which has towards its forward end; a radially projecting retention collar 94 integral with said rod, said collar 94 being adapted to be accommodated within recess 80 provided in the inner surface of the segment assembly towards the forward end thereof. The forward end 96 of the support rod 92 terminates flush with the forward end of the segment assembly, and is provided with an axial blind bore 98 which is tapped to receive a threaded screw 100.

A front plate 102 of substantially frusto-conical form is arranged so that the portion of the largest diameter is contiguous the forward end of the mandrel assembly. The front plate is provided with an axial bore and the face of the front plate is counter-sunk to receive the head of screw 100 for securing the front plate 102 to the support rod 92. The rearward face of the front plate 102 contiguous the front face of the mandrel assembly is provided with a rearwardly extending annular flange constituting a hinge 104, said flange 104 being rounded at its rearward end, and adapted to be received within the peripheral recess 86 defined by the rabbet between the arcuate outer surface and the annular front face of the mandrel assembly.

The support rod 92 projects rearward of the mandrel assembly and is threaded at its rearward end 106. The support rod 92 carries a taper element 108 defined by a frusto-cone terminating at its rearward end in a radial 7 housing 112. The rearward movement of the support annular flange 110, the frusto-cone of the taper reducing forwardly of said flange, the walls of the frusto-cone being inclined to the axis of the rod 92 and segment assembly to correspond with the inclination of the walls defining the frusto-conical passage 84 at the rear of segment assembly.

The flange 110 of the taper element 108 is provided with the plurality of circumferentially spaced bolt holes, and is arranged to be secured to the housing 112. The taper element 108 is provided with a central bore 114 through which the support rod 92 passes and is arranged from the sliding movement of the rod 92 within said central bore 114. The taper element 108 is typically formed of phosphur bronze or hardened steel and extends into the frusto-conical passage 84 at the rear ward end of the segment assembly to abut the same, the abutting portion of each segment 70 being hardened to increase the wear resistance thereof.

The threaded end 106 of the support rod is connected by means of a connecting portion to the operating rod of the ram.

In operation, the shaft 55 is rotated to move fulcrum carriage 50 along the shaft to select the appropriate fulcrum position for the axis of fulcrum pin 65 with respect to longitudinal slot and cylinder 10. On producing relative rotation between the cylinder assembly 10 and the support 45 on the one hand and the cam drum 35 on the other, the ball end of rocker arm 25 is caused to follow the oscillation of groove 37 about the cylindrical surface 36 of drum 35 and is therefore caused to execute an arcuate motion about fulcrum pin 65 which is fixed with respect to cylinder 10. Starting from its datum position, as ball end 31 moves forwardly in response to the forward disposition of groove 37 in the surface of drum 35, the arm 25 pivots about fulcrum pin 65 to move bifurcated portion 26 rearwardly with respect to its initial datum position, thereby moving connecting pin with piston 16 connected therewith rearwardly within cylinder 10. The pin 20 is constrained to execute linear reciprocating motion in a manner defined by its coupling with piston 16. As, therefore, the throw of connecting pin 20 commences, the arm executes a pivotal movement with respect to fulcrum pin 65, and the floating fulcrum pin 65 with its associated slider 66 moving within slot 33, permits the arm 25 to float downwardly in response to the constraint imposed by the requirements of linear reciprocating motion of the connecting pin 20. With continued relative rotation between the drum the rocker arm assembly and the ball end of arm 25 moves forwardly rod 92 produces corresponding rearward movement of the retention collar 94 and of the segment assembly is secured thereto by means of the front plate 102. The tapered inner surface at the rear of the segment assembly is caused to ride up the taper element 108 with the result that the dimensions of the segmented assembly are increased at the rearward end. Each segment 70 of the assembly is caused, therefore, to hinge outwardly about the hinge flange 104 of the front plate 102, to define a frusto-conical taper along the length of the segment assembly the extent of which is determined by the distance the support rod 92 is caused tomove rearwardly with respect to the taper element 108. The greater the distance moved, the greater the taper imparted to the expanded segment assembly.

On releasing or returning the operating rod of the ram to its normal position, the support rod 92 moves forwardly with respect to the taper, and the rearward end of the segment assembly is withdrawn forwardly from the taper element 108 until the radial sides 76 of the segments 70 each abut the contiguous segments, under the action of the spring clips 116 provided in the peripheral recesses 88, 90 in the reduced portion of the rearward end of the segment assembly.

In order to adjust the maximum throw of connecting pin 20 in response to a constant horizontal throw of ball end 31 of dimension A shown in FIG. 1, it will be appreciated that by adjusting shaft 55 to move fulcrum carriage upwardly or downwardly along shaft 55, the position of the fulcrum pin will be altered relative to cylinder 10 and its associated piston assembly with the result that the throw applied to piston 16 via arm 25 will be altered; thus, if the carriage 50 moves upwardly along shaft 55, the relative position of fulcrum pin with respect to cylinder 10 will be such as to reduce the said throw, while movement of the carriage 50 downwardly along shaft 55 will effectively increase the relative distance between connecting pin 20 and fulcrum pin 55 and to provide a smaller distance between fulcrum pin 65 in the center of ball end 31 with the result that the throw applied to the connecting pin 20 will be substantially increased.

Thus, it will be appreciated that it is possible by use of apparatus in accordance with the present invention to provide a variable throw rocker arm assembly which will enable the throw of the operating rod l4-of the mandrel to be altered at will to accommodate different sizes of tube and yet at the same time enable the rod to consistently index a pre-determined datum position.

What I claim is:

1. Actuating means for a mandrel assembly of the type having a plurality of discreet longitudinal segments which together constitute a segment assembly to define a generally cylindrical mandrel surface, hinge means provided towards one end of said assembly to permit each of said segments to hinge radially outwardly of the longitudinal axis of said cylindrical surface at least towards one end thereof, expansion means adapted to urge said segments outwardly and about said hinge means at said one end of the segment assembly so that the outer surface of the segments together define a taper and operating means for producing relative motion between said segments and said expansion means between an inoperative position in which the segments define a substantially cylindrical mandrel surface and an expanded position in which the segments define a taper surface, the operating means comprising a longitudinal rod adapted to draw said segment assembly onto said expansion means, said actuating means comprising: a rocker arm adapted to drive the rod, said arm having a first part and a second part, said first part being coupled to the rod and being adapted in response to actuation of said arm to execute a linear reciprocating motion from a datum position at an extremity of said motion; floating fulcrum means for said arm disposed intermediate said first and said second parts; and adjustment means for varying the position of said fulcrum with respect to the datum position of said first part and in a plane containing or parallel to the datum position of said first part and said second part of said arm, whereby the throw of the longitudinal rod can be varied by operation of said adjustment means while maintaining said one extremity of said motion of said first part and the rod connectedthereto in said datum position for varying the taper imparted to the segment assembly in its expanded position.

2. An actuating means as claimed in claim 1 wherein the second part of said rocker arm is adapted to cooperate with a cam track provided in the cylindrical surface of a drum.

3. An actuating means as claimed in claim 2 wherein the cam drum is fixed and the rod and actuating means are rotatable circumferentially around the drum axis whereby the rocker arm is caused to rock about its fulcrum due to inter action between the second part of said arm and said cam track.

4. An actuating means as claimed in claim 1 wherein the floating fulcrum means comprises a longitudinal slideway intermediate said first and said second part of said arm and a fulcrum pin assembly disposed for relative sliding movement therein.

5. An actuating means as claimed in claim 4 wherein the fulcrum pin assembly comprises a fulcrum pin mounted in a carriage slidably supported by a fixed bracket provided therefor.

6. An actuating means as claimed in claim 5 wherein the. bracket includes an adjustment screw which engages a corresponding threaded bore on said carriage whereby the position of said carriage and said fulcrum pin may be moved relative to the datum position of said first part.

7. An actuating means as claimed in claim 1 wherein the rocker arm includes an intermediate portion of generally rectangular cross-section which increases in cross-sectional dimension towards its mid point and wherein the second part of said rocker arm is generally frusto-conical in form and terminates in a spheroidal ball portion integral therewith.

8. An actuating means as claimed in claim 7 wherein the said ball portion is adapted to enter into and cooperate with a continuous cam groove provided in a cylindrical surface of a cam roller whereby upon relative rotation between said roller and said rocker arm reaction between the ball portion of the rocker arm and the cam groove causes said arm to rock about its fulcrum pin. 

1. Actuating means for a mandrel assembly of the type having a plurality of discreet longitudinal segments which together constitute a segment assembly to define a generally cylindrical mandrel surface, hinge means provided towards one end of said assembly to permit each of said segments to hinge radially outwardly of the longitudinal axis of said cylindrical surface at least towards one end thereof, expansion means adapted to urge said segments outwardly and about said hinge means at said one end of the segment assembly so that the outer surface of the segments together define a taper and operating means for producing relative motion between said segments and said expansion means between an inoperative position in which the segments define a substantially cylindrical mandrel surface and an expanded position in which the segments define a taper surface, the operating means comprising a longitudinal rod adapted to draw said segment assembly onto said expansion means, said actuating means comprising: a rocker arm adapted to drive the rod, said arm having a first part and a second part, said first part being coupled to the rod and being adapted in response to actuation of said arm to execute a linear reciprocating motion from a datum position at an extremity of said motion; floating fulcrum means for said arm disposed intermediate said first and said second parts; and adjustment means for varying the position of said fulcrum with respect to the datum position of said first part and in a plane containing or parallel to the datum position of said first part and said second part of said arm, whereby the throw of the longitudinal rod can be varied by operation of said adjustment means while maintaining said one extremity of said motion of said first part and the rod connected thereto in said datum position for varying the taper imparted to the segment assembly in its expanded position.
 2. An actuating means as claimed in claim 1 wherein the second part of said rocker arm is adapted to co-operate with a cam track provided in the cylindrical surface of a drum.
 3. An actuating means as claimed in claim 2 wherein the cam drum is fixed and the rod and actuating means are rotatable circumferentially around the drum axis whereby the rocker arm is caused to rock about its fulcrum due to inter action between the second part of said arm and said cam track.
 4. An actuating means as claimed in claim 1 wherein the floating fulcrum means comprises a longitudinal slideway intermediate said first And said second part of said arm and a fulcrum pin assembly disposed for relative sliding movement therein.
 5. An actuating means as claimed in claim 4 wherein the fulcrum pin assembly comprises a fulcrum pin mounted in a carriage slidably supported by a fixed bracket provided therefor.
 6. An actuating means as claimed in claim 5 wherein the bracket includes an adjustment screw which engages a corresponding threaded bore on said carriage whereby the position of said carriage and said fulcrum pin may be moved relative to the datum position of said first part.
 7. An actuating means as claimed in claim 1 wherein the rocker arm includes an intermediate portion of generally rectangular cross-section which increases in cross-sectional dimension towards its mid point and wherein the second part of said rocker arm is generally frusto-conical in form and terminates in a spheroidal ball portion integral therewith.
 8. An actuating means as claimed in claim 7 wherein the said ball portion is adapted to enter into and co-operate with a continuous cam groove provided in a cylindrical surface of a cam roller whereby upon relative rotation between said roller and said rocker arm reaction between the ball portion of the rocker arm and the cam groove causes said arm to rock about its fulcrum pin. 